The invention relates to an electronic circuit arrangement for triggering solenoid valves.
These types of circuit arrangements are used, for example, to trigger the excitation windings of solenoid valves, as find application in particular in the open-loop control of injection systems for combustion engines.
The known electronic circuit arrangements used in injection systems for combustion engines require a relatively complex circuitry to trigger the solenoid valves. On the one hand, this results in a relatively high manufacturing price, while on the other hand, however, the electronic components also require a suitable space.
The JP-A-5 854 611 discloses an electronic circuit arrangement of two excitation windings of an electromagnet, in the case of which the excitation windings are connected in series to a controllable contact element in the form of switching transistors. Both excitation windings of the electromagnet can be connected via a break device to a power supply device. Furthermore, a free-wheeling circuit, which comprises one series connection each of a diode and of a Zener diode, is provided for each excitation winding. From the document DE-A-2 452 077, one knows of a triggering and current-recovery circuit for the printer magnets of a high-speed printer, in the case of which a multitude of excitation windings are connected in series both by means of contact elements as well as by means of diodes to a current source. One connecting terminal each of all excitation windings is connected to a shared line, which is connected in the closed-circuit condition via a contact-break distance of a switching transistor and in the blocked condition via a diode, which is poled in the blocking direction, to a power supply device. The electromagnets are disconnected by switching over the contact elements assigned to each of the excitation windings, whereby the excitation windings are separated from the power supply unit and from a capacitor contained therein. The induction voltage induced in the excitation windings of the electromagnets is fed back into the power supply unit via the diode, which is assigned to each excitation winding and switched for this voltage in the conducting direction.